Add.
Answer: First, let's jump $3$ on the number line. $0$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$ $+3$ Next, let's jump $1$ on the number line. $0$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$ $+3$ $+1$ The jumps end at the number $4$. $+3$ $+1$ $\boxed{4}$ $0$ $1$ $2$ $3$ $5$ $6$ $7$ $8$ $9$ $10$ $4=3 + 1$